Three pro-Spain political parties have filed complaints at the Constitutional Court over moves by Catalonia's regional parliament to announce the formal start of secession from Spain.

Catalan branches of Spain*s ruling conservative Popular Party, and the Socialist and Citizens parties, filed the appeals Wednesday.

The protest came after secessionist parties used their majority in the Catalan parliament to begin procedures for a secession announcement next week.

The motion was pushed by the "Together for Yes" pro-independence alliance, which won 62 seats in Catalonia's 135-member regional parliament in September elections, along with the radical leftist CUP party that won 10 seats. The two are in talks to form a new regional government.

The Spanish government rules out any possibility of Catalan independence and intends to challenge the proposal.